Novel photoresist monomers, polymers thereof, and photoresist compositions using the same are disclosed. In particular, chemical amplification photoresist polymers and photoresist compositions are disclosed which are suitable for a photolithography process using a light source such as VUV (157 nm) in fabricating a minute circuit for a highly integrated semiconductor device.
In general, a useful photoresist for ArF or VUV (vacuum ultraviolet) should have low absorbency at 193 nm and 157 nm wavelengths, excellent etching resistance and adhesiveness on the substrate, and should be able to be developed in a commercially available developing solution, such as 2.38 wt % and 2.6 wt % aqueous tetramethylammonium hydroxide (hereinafter abbreviated to as xe2x80x9cTMAHxe2x80x9d) solution.
Recently, much research has been conducted on resins having a high transparency at a wavelength of 248 nm and 193 nm and dry etching resistance similar to novolac resin. However, most of these photoresists cannot be deposited in a sufficient thickness to render a suitable dry etching resistance. Also, these recently developed resins have poor transmittance at 157 nm wavelength.
A photoresist for 157 nm should have excellent etching resistance, heating resistance and adhesiveness on the substrate, and should be able to be developed in 2.38 wt % aqueous TMAH solution as a conventional developing solution. However, it is very difficult to synthesize such a polymer that satisfies all these requirements.
For use of a light source of a short wavelength (157 nm), photosensitive agents are available with transparency for the light source of 157 nm, but the available organic photoresist polymers absorb light having a wavelength of 157 nm.
Thus, the primary problem to be solved first when forming a micro pattern of 100 nm or less by using extremely short wavelength (157 nm) is to develop a photoresist polymer which has excellent etching resistance, heat resistance, adhesive property and good transmittance at 157 nm wavelength, and which can be developed in conventional 2.38 wt % aqueous TMAH developing solution.
Therefore, there is a need for a photoresist composition that overcomes the above-mentioned disadvantages.
Chemical amplification photoresist monomers containing imide and fluorine which has appropriate transmittance of a light source of 157 nm in a photolithography process are disclosed.
Photoresist polymers containing the above photoresist monomers and which has appropriate transmittance of a light source of 157 nm in a photolithography process are also disclosed.
Photoresist compositions containing the photoresist polymers described above and a process for forming a photoresist pattern using the photoresist composition are also disclosed.
Semiconductor elements produced using the photoresist composition described above are also disclosed.